HKUST Engineers Develop Full-Color Fiber LEDs for Advanced Wearable Displays

HKUST Engineers Develop Full-Color Fiber LEDs for Advanced Wearable Displays
by Simon Mansfield
Sydney, Australia (SPX) Aug 13, 2024

A team of researchers from the School of Engineering at the Hong Kong University of Science and Technology (HKUST) has made significant strides in wearable technology by creating full-color fiber light-emitting diodes (Fi-LEDs) using perovskite quantum wires (PeQWs). This innovation is expected to play a key role in the development of new wearable lighting and display systems.

Fi-LEDs have garnered attention in the field of flexible LEDs due to their compatibility with textiles and their ability to provide uniform brightness across large surfaces. Metal halide perovskites (MHPs) have emerged as ideal materials for next-generation LEDs, thanks to their exceptional light-emitting properties. However, the production of MHP-based Fi-LEDs has been challenging due to issues like uneven coating, poor crystallization, and complex electrode placement, all of which have hindered efficient light emission.

To overcome these challenges, the HKUST research team, led by Prof. FAN Zhiyong, Chair Professor of the Department of Electronic and Computer Engineering and the Department of Chemical and Biological Engineering, developed a novel method involving porous alumina membrane (PAM) templates on thin aluminum fibers. The PAM, which has an ultra-small pore size of approximately 5 nanometers, was created using a roll-to-roll solution-coating process. The MHP precursor solution was then introduced into the PAM channels, followed by an annealing process that ensured even solvent evaporation and crystallization of the MHPs. This approach allowed for the uniform growth of PeQW arrays and reduced the formation of undesired thin films on the PAM surface.

The researchers successfully produced full-color Fi-LEDs with emission peaks at 625 nm (red), 512 nm (green), and 490 nm (sky-blue). These fibers demonstrated excellent flexibility and durability, making them ideal for use in textile-based lighting. The team showcased various 2D and 3D designs, including a 2D string that read "I ? HKUST" and a "night scene" of Victoria Harbor, both of which displayed remarkable fluorescence uniformity and color variation.

This development marks a major step forward in Fi-LED technology. Looking ahead, the team aims to further improve the efficiency and durability of these devices, explore new perovskite materials to expand the color range, and integrate Fi-LEDs into commercial textiles.

"The combination of quantum confinement effect and the passivation from the 3D porous alumina membrane structure has enabled us to achieve outstanding photoluminescence and electroluminescence efficacy. Our innovative approach for fiber LEDs opens up new possibilities for fabricating unconventional 3D-structured lighting sources, paving the way for advanced wearable display technologies," said Prof. Fan.

Research Report:Full-color fiber light-emitting diodes based on perovskite quantum wires